Distilling oil with aluminum chloride



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ALMEB MCDUFFIE IVIOAFEE, OF PORT ARTHUR, TEXAS, ASSIGNOR TO GULF REFINING GOMIANY, OF PITTSBURGH, PENNSYLVANIA, A CORYQR-ATION OF TEXAS.

DISTILLING OIL WITH ALUMINUM CHLORTDE.

No Drawing. firiginal application filed September 30, 1913, Serial No. 792,615,. Divided and this application filed January 13, 1922. Serial No. 529,071.

To all whom it may concern:

Be it known that I, ALMER MCDUFFIE MCAFEE, a citizen of the United States, residing at Port Arthur, in the county of Jefferson and State of Texas, have invented certain new and-useful Improvements in Distilling Oils with Aluminum Chloride,

of which the following is a specification.

This invention relates to distilling oils m with aluminum chloride; and it comprises a method of distilling oils with anhydrous I aluminum chloride for the purpose of producing oils of lowered boiling point (gasoline, etc.) wherein heat is economized .and the capacity increased by maintaining the system under pressure above that of atmosphere; all as more fully hereinafter set forth and as claimed.

In another and copending application, Serial No. 7 92,615, filed September 30, 1913, of which this application is a division, I have described and claimed a process of distilling various high boiling petroleum oils, such as gasoil, solar oil, etc., with aluminum chloride for the purpose of producing oils of lowered boiling point, such as gasoline and kerosene. In this method, the hot oil is admixed with a small amount of anhydrous aluminum chloride, usually about 5 per cent. The aluminum chloride combines or me down with a portion of the oil to form a heavy oil, which is kept stirred up through the oil by powerful agitating means. The mixture is distilled and the vapors are cooled somewhat in a reflux condenser prior to being sent to the final or water cooled condenser. This reflux cooling is necessary to hold back the aluminum chloride which tends to volatilize- Otherwise, the bath would be stripped of aluminum chloride and aluminum chloride would pass forward to the condenser with the gasoline, etc. Ordinarily, the exit temperature of the vapors leaving the reflux condenser is held around BOO-350 F.

In the process as described in said application, operation is described as at the ordinary or atmospheric pressure, and it is stated that pressure may be used, but operation under pressure is not specifically claimed.

Pressure is in some instances economical and desirable.

Looked at in one way,

the operation as.

.500 to 550 F.; but a large number 'just described is a simple distillation; the gas oil introduced into the still being distilled as gasoline, and, as in any operation involving volatilization, the consumption of heat is rather great. The temperature required is not high, being, with gas oil, around of heat units must be delivered at that temperature plane. The use of the reflux condenser a considerably to the demand for heat, since the heat units dissipated in the condenser must be furnished to the still; or stated in another way, the material which has once been distilled and has been condensed and refluxed must. be again distilled. Anything which will cut down the consumption of heat units in the reflux adds to the economy of operation; and further, by cutting down the demands in the reflux condenser densation of high boiling materials, the capacity of the system is increased, since a greater proportion of the vapors evolved in ebullition then goes forward to the final condenser. These advantages 1 am able to secure by the use of pressure.

Presuming gas oil to be employed, its boiling point is ordinaril somewhere; around 600 F. On the addition of fresh active aluminum chloride, vigorous ebullition begins at about 475 F, and the ebullition temperature throughout the rest of the operation usually runs somewhere between 500 an initial boiling point very far below that.

In other words, the action going forward at 500-550 F. is the production of a substance which is a vapor at temperatures much below dds for cond 550 F; the particular temperature dependthis point. In boiling at atmospheric pressure at 500550 F, the gasoline vapors evolved are accompanied by comparatively large amounts of vapors of aluminum chloride, or of its compounds with hydrocarbons,

and of the gas oil, as well as large amounts of kerosene formed by the action of aluminum chloride on the gas oil.

By maintaining the whole system under a pressure .of 15 to 50 pounds by the use of a suitable weighted valve, which may be lo cated between the still and condenser or beyond the condenser, the evolution of vapors of high boiling materials, that is of gas oil, of aluminum chloride compounds and of kerosene is much cut down while the evolution of gasoline vapors is not greatly interfered with. As stated, gasoline is a va or at temperatures far below 500-550 F. and

- it is still vapor under the pressures noted.

The pressure does not materially cut down evolution of gasoline vapors although diminishing thatof high boiling stuff and it does not materially raise the temperature of ebullition since this, as noted, is due to chemical action rather than boiling. The temperature does however rise a few degrees which results in the production of much more ,copious evolution of gasoline vapors, this production in turn, automatically cutting down a further rise. The net result is a greater production of gasoline and a less condensation in the reflux, with a concomitant lessening of the heat demands in the operation.

What I claim is n In the conversion of oils into products of lowered boiling point, the process which comprises distilling a high boiling oil with.

anhydrous aluminum chloride greater than atmospheric.

In testimony whereof, I have hereunto afiixed my signature.

ALMER MoDUFFIE MCAFEE.

at a ,pressure 

